CLINICAL ASSESSMENT OF RENAL FUNCTION IN THE DOG WITH A REDUCTION IN NEPHRON NUMBER*

The viewpoint presented is that, because compensatory functional adjustment of the residual nephrons occurs in chronic renal disease, reduction in nephron number usually exceeds 70% before a diagnosis is made. The case that earlier diagnoses are likely if laboratory medicine values are measured and interpreted with a maximum of efficiency is then made. The laboratory data more commonly used in practice for the clinical assessment of renal function in the dog are presented and some comparisons with findings in man are made. The information originates from clinical and experimental observations of the authors, as well as from a literature review. The laboratory data presented and discussed includes glomerular filtration rate and the clearance of nitrogenous waste (urea and creatinine), plasma protein concentration, plasma osmolality, renal concentrating capacity, and urinary constituents, particularly its protein concentration and sediment (centrifuge deposit). All parameters recommended for the clinical assessment of chronic renal failure are considered qualitatively, and some are also dealt with quantitatively.     

Aortic interruption in a dog.

A 3-month-old English Bulldog was found to have a discontinuity between the ascending and descending aorta. There were no signs of illness associated with the interruption. The descending aorta was supplied with blood by collateral circulation. An aortic graft of woven synthetic material was surgically implanted to connect the ascending and descending aorta. Without any restrictions on the dog's activity, the dog has lived for over 1 year and continues to do well.     

Colorectal polyps of the dog: a clinicopathologic study of 17 cases.

Seventeen cases of colorectal polyps in the dog were seen at the Ontario Veterinary College over a 12-year period. The mean age of occurrence was 6.9 years, and males and females were almost equally affected. The Collie was the most frequently affected breed (4/17). The clinical signs were typically dyschezia, periodic intermittent diarrhea and melena, and rectal prolapse of the polyp. The histopatholic classifcation were hyperplastic polyp (1), papillary adenoma (1), tubular adenoma (4), papillotubular adenoma (10), and unclassified (1). Severe epithelial atypia, likely carcinoma in situ, was apparent in 5 of the papillotubular adenomas. Retrospective analysis of survival data after polypectomy suggested a good prognosis, but the results were inconclusive and it is possible that some of the polyps represented premalignant lesions. Large polyps (greater than 1 cm in diameter) frequently had marked epithelial atypia and were considered more likely to recur or to become malignant.     

Observations on the selenium status of cattle in the north-east of Scotland.

Cattle on 18 of 21 farms in north-east Scotland were found to have low whole blood activities of the selenium-containing enzyme, glutathione peroxidase (less than 5 units per ml whole blood), and a low blood concentration of selenium (less than 0.05 mg per litre). These cattle had all been fed on locally produced feedstuffs without any mineral supplementation. The low selenium status in cattle occurred on farms with soils derived from a range of parent material, no one particular type predominating.     

Trombiculosis in a cat.

Trombiculosis (dermatitis caused by trombiculid mites) in a Domestic Shorthair cat was characterized by diffuse thickening and crusting of the skin of the abdomen and limbs and by multiple papules on the face, ears, and sides of the trunk. Skin biopsy revealed acanthosis and hyperkeratosis involving the epidermis and hair follicles, mites in epidermal tunnels, and edema of the dermis, with infiltration of eosinophils and mast cells. Mites from skin scrapings were identified as Walchia americana. The cat was treated systemically with a broad-spectrum antibiotic and topically with a carbaryl and pyrethrin powder preparation. The lesions were resolved within 2 months.     

Mycotic pneumonia in mariculture-reared green sea turtles

Microbiologic examination of 29 juvenile green sea turtles with a buoyancy abnormality revealed pulmonary infection with Sporotrichium sp, Cladosporium sp, and Paecilomyces sp. Histologic examination of the lungs revealed granulomatous lesions containing branching septate hyphae. The diagnosis was mycotic pneumonia.